JP7157958B2 - pressure sensitive elements and steering gear - Google Patents

Description

The present disclosure relates to pressure sensitive elements and steering systems.

2. Description of the Related Art Pressure-sensitive elements are widely used in the fields of industrial equipment, robots, vehicles, and the like by being attached to parts touched by people as pressure-sensitive sensors that detect pressing force (contact pressure). 2. Description of the Related Art In recent years, along with the development of computer control technology and the improvement of design, the development of electronic devices such as humanoid robots and interior parts of automobiles that use free-form surfaces in various ways is progressing. Accordingly, it is required to mount a high-performance pressure-sensitive element on each free-form surface. For example, Patent Documents 1 to 3 disclose these background techniques.

JP 2011-102457 A JP 2015-114308 A JP 2014-190712 A

As a result of intensive studies, the inventors of the present application have found that a pressure-sensitive element used as a capacitance-type pressure-sensitive sensor has improvements in terms of a pressure measurement range (dynamic range) and structural simplification. found out.

Specifically, in the technique of Patent Document 1, since the pressing force is detected by using the change in capacitance based on the change in the distance between the conductive yarns, there is a problem that the pressing force measurement range is relatively narrow. was becoming

In the technique disclosed in Patent Document 2, since it is necessary to connect detection elements with a connecting portion having a crank-shaped bending structure, simplification of the structure of the pressure-sensitive element has been demanded.

In the technique disclosed in Patent Document 3, the load sensor unit includes an elastomer base material and front-side electrodes and back-side electrodes arranged on the front side and the back side of the base material, respectively. is detected. Therefore, there is a problem that the pressing force can be measured in a relatively narrow range.

The present disclosure has been made in view of such circumstances. That is, an object of the present disclosure is to provide a pressure-sensitive element that has a relatively wide pressure measurement range and a relatively simple structure.

A pressure-sensitive element according to the present disclosure is a pressure-sensitive element that includes a pressure-sensitive portion to which a pressing force is applied and a detector that detects the pressing force, wherein the pressure-sensitive portion is an elastic sheet-like A first conductive member made of conductive rubber, a second conductive member, disposed between the first conductive member and the second conductive member, and covering the surface of the second conductive member a dielectric, wherein the second conductive member is a metal wire, the dielectric constitutes an insulating coating of the second conductive member, and the dielectric and the second conductive member have an insulating coating. The detector comprises a metal wire, the dielectric has rigidity, and the pressure sensing portion is applied with the pressing force, so that the first conductive member or the second conductive member and the dielectric Based on the change in the capacitance between the first conductive member and the second conductive member due to the area of the contact region with expanding based on the elasticity of the first conductive member to detect the pressing force.

According to the present disclosure, it is possible to obtain a pressure-sensitive element having a relatively wide measuring range of pressing force and having a relatively simple structure.

FIG. 1A is a cross-sectional view schematically showing the configuration of a pressure-sensitive element according to the first embodiment of the present disclosure; FIG. FIG. 1B is a cross-sectional view schematically showing the configuration of the pressure-sensitive portion of the pressure-sensitive element of FIG. 1A when a pressing force is applied to the pressure-sensitive portion. 1C is a diagram schematically showing an example of a plan view shape of a second conductive member in the pressure-sensitive element of FIG. 1A and an example of a restraining member that limits positional displacement of the second conductive member; FIG. 4 is a schematic view of the material and the second conductive member when viewed from the side of the second conductive member; FIG. 1D is a cross-sectional view schematically showing the configuration of a pressure-sensitive element according to a modification of the first embodiment of the present disclosure; FIG. 1E is a cross-sectional view schematically showing the configuration of the pressure-sensitive portion of the pressure-sensitive element of FIG. 1D when a pressing force is applied to the pressure-sensitive portion. FIG. 2 is a cross-sectional view schematically showing the configuration of a pressure-sensitive element according to the second embodiment of the present disclosure. FIG. 3 is a cross-sectional view schematically showing the configuration of a pressure-sensitive element according to the third embodiment of the present disclosure. FIG. 4 is a cross-sectional view schematically showing the configuration of a pressure-sensitive element according to the fourth embodiment of the present disclosure. FIG. 5 is a cross-sectional view schematically showing the configuration of a pressure-sensitive element according to the fifth embodiment of the present disclosure. FIG. 6A is a cross-sectional view schematically showing the configuration of a pressure-sensitive element according to the sixth embodiment of the present disclosure; FIG. 6B is a sketch of the first conductive member and the second conductive member, schematically showing the configuration of the first conductive member and the second conductive member in the pressure-sensitive element of FIG. 6A. FIG. 7 is a cross-sectional view schematically showing the configuration of a pressure-sensitive element according to the seventh embodiment of the present disclosure. FIG. 8 is a cross-sectional view schematically showing the configuration of a pressure-sensitive element according to the eighth embodiment of the present disclosure. FIG. 9A is a cross-sectional view schematically showing the configuration of a pressure-sensitive element according to the ninth embodiment of the present disclosure; FIG. 9B is a cross-sectional view schematically showing the configuration of the pressure-sensitive portion of the pressure-sensitive element of FIG. 9A when a pressing force is applied to the pressure-sensitive portion. FIG. 10A is a cross-sectional view schematically showing the configuration of a pressure-sensitive element according to the tenth embodiment of the present disclosure; FIG. 10B is a cross-sectional view schematically showing the configuration of the pressure-sensitive portion of the pressure-sensitive element of FIG. 10A when a pressing force is applied to the pressure-sensitive portion. FIG. 10C is a cross-sectional view schematically showing the configuration of another pressure-sensitive element according to the tenth embodiment of the present disclosure; FIG. 10D is a cross-sectional view schematically showing the configuration of another pressure-sensitive element according to the tenth embodiment of the present disclosure; 11A is an enlarged cross-sectional view schematically showing a first conductive member and a second conductive member having a dielectric on its surface in an example of a pressure-sensitive element according to the eleventh embodiment of the present disclosure; FIG. 11B is an enlarged cross-sectional view schematically showing a first conductive member and a second conductive member having a dielectric on its surface in another example of the pressure-sensitive element according to the eleventh embodiment of the present disclosure; FIG. . FIG. 12 is a schematic diagram showing an example of a steering device (steering wheel) according to a twelfth embodiment to which the pressure-sensitive element of the present disclosure is applicable. FIG. 13A is a cross-sectional view schematically showing an example of a steering device (steering wheel) according to the twelfth embodiment, to which the pressure-sensitive element of the present disclosure is applied; 13B is an enlarged cross-sectional view of a partial region R of the steering device shown in FIG. 13A.

Details of the pressure-sensitive element according to the present disclosure and the application of the pressure-sensitive element will be described with reference to the drawings.

[Pressure sensitive element]
A pressure-sensitive element of the present disclosure is an element having capacitance and has a capacitor function or a capacitor function. In such a pressure-sensitive element, application of a pressing force causes a change in capacitance, and the pressing force is detected from the change in capacitance. Therefore, the pressure-sensitive element of the present disclosure is also called a "capacitive pressure-sensitive sensor element", a "capacitive pressure detection sensor element", or a "pressure-sensitive switch element".

The pressure-sensitive element according to the present disclosure will be described below with reference to the drawings. It should be noted that various elements shown in the drawings are only schematically shown for understanding of the present disclosure, and dimensional ratios, appearances, etc. may differ from the actual ones. The term "vertical direction" used directly or indirectly in this specification corresponds to the vertical direction in the drawings. Also, unless otherwise specified, the same reference numerals or symbols indicate the same members or the same meanings. The following (first embodiment) to (eleventh embodiment) and modifications thereof are embodiments and modifications related to the pressure-sensitive element.

(First embodiment)
FIG. 1A schematically shows the configuration of a pressure-sensitive element 100A of this embodiment. That is, FIG. 1A is a cross-sectional view schematically showing the configuration of a pressure-sensitive element 100A according to the first embodiment. A pressure-sensitive element 100A of this embodiment includes a pressure-sensitive portion 1A to which a pressing force is applied and a detector 2A that detects the pressing force.

(1a) pressure sensing section 1A
The pressure sensing portion 1A has a first conductive member 11, a second conductive member 12 and a dielectric 13. As shown in FIG. Although the dielectric 13 covers the surface of the second conductive member 12 in FIG. 1A, it may cover the surface of either the first conductive member 11 or the second conductive member 12 .

FIG. 1B is a cross-sectional view schematically showing the configuration of the pressure sensing portion 1A when a pressing force is applied to the pressure sensing portion 1A of the pressure sensing element 100A of FIG. 1A.

In the pressure-sensitive element 100A of this embodiment, as shown in FIG. 1B, when a pressure F is applied to the pressure-sensitive portion 1A, the dielectric material of the first conductive member 11 and the second conductive member 12 The area of the contact region between the conductive member (the first conductive member 11 in FIGS. 1A and 1B) and the dielectric 13 where the conductive member 13 is not covered (hereinafter sometimes simply referred to as the “area of the contact region”) is It increases based on the elasticity of the first conductive member 11 . As a result, the capacitance C [pF] between the first conductive member 11 and the second conductive member 12 changes. Since the capacitance C [pF] and the pressing force F [N] applied to the pressure sensing portion are expressed by the following (Equation 1) and (Equation 2) respectively, the pressing force F is detected by the detector 2A. be. In this embodiment, the pressing force F is detected based on the change in the area of the contact area as described above.

In (Equation 1) and (Equation 2), ε [pF/m] is the dielectric constant of the dielectric, S [m ² ] is the contact area between the conductive member not covered with the dielectric and the dielectric, d [m] is the thickness of the dielectric, E [Pa] is the Young's modulus of the first conductive member, and e is the strain of the first conductive member.

In the conventional pressure-sensitive element, the change in the capacitance C is captured by the change in the distance between the electrodes, and the pressing force F is detected. On the other hand, in the pressure-sensitive element of this embodiment, the pressing force F is detected by capturing the change in the capacitance C based on the change in the area of the contact area. In the change of the capacitance C, the contribution due to the change in the area of the contact region is larger than the contribution due to the change in the distance between the electrodes. In particular, when the magnitude of the pressing force F is small, the application of the pressing force F hardly changes the distance between the electrodes, so the change in the capacitance C due to the change in the distance between the electrodes is very small. On the other hand, even if the magnitude of the pressing force F is small, the application of the pressing force F causes a change in the area of the contact area. This is because the capacitance C is proportional to the area of the contact area, but inversely proportional to the distance between the electrodes (C∝S, C∝1/d). Therefore, the pressure-sensitive element of this embodiment has a wider measurement range of the pressing force F than the conventional pressure-sensitive element.

The pressure-sensitive portion 1A in the pressure-sensitive element of this embodiment may be applied with a pressing force from either the first conductive member 11 or the second conductive member 12, but normally the second A pressing force is applied from the conductive member 11 side of 1 . FIG. 1B shows that a pressing force is applied from the side of the first conductive member 11, and due to its reaction, force also acts from the side of the base material 14, which will be described later.

The first conductive member 11 has elastic properties and conductive properties and functions as a so-called electrode. The elastic property is the property of being locally deformed by an external force and returning to its original shape when the force is removed. The external force is a normal pressing force applied to the pressure-sensitive element, and its magnitude is, for example, approximately 0.1 N/cm ² or more and approximately 100 N/cm ² or less. Specifically, the first conductive member 11 may have such an elastic property that the area of the contact area between the first conductive member 11 and the dielectric 13 is enlarged by the pressing force applied to the pressure sensitive portion. . Specifically, the first conductive member 11 may have a lower elastic modulus than the dielectric 13 so as to deform more than the dielectric 13 when pressed. From the viewpoint of further expanding the pressing force measurement range and improving pressure sensitivity, the elastic modulus of the first conductive member 11 is preferably, for example, about 10 ⁴ Pa or more and about 10 ⁸ Pa or less. Then, it is about 10< ⁶ >Pa. As the elastic modulus of the first conductive member 11 increases within the above range, the pressing force can be measured in a wider range. As the elastic modulus of the first conductive member 11 is smaller within the above range, the pressure sensitivity is improved. If the pressure sensitivity is improved, for example, it becomes possible to detect even a very small pressing force that is difficult to detect in the conventional art. Accordingly, it becomes possible to accurately detect the start of application of the pressing force. Regarding the conductive properties, the resistivity of the first conductive member 11 may be sufficiently smaller than the impedance of the capacitance in the desired frequency band. Such resistivity can be adjusted by changing the relative proportions of the conductive filler and the resin material (rubber material), which will be described later.

The first conductive member 11 corresponds to an elastic electrode member and can also be called an elastic member. The first conductive member 11 may be made of any material as long as it has both the elastic property and the conductive property as described above. For example, the first conductive member 11 may be made of a conductive resin comprising a resin material (particularly a rubber material) and conductive filler dispersed in the resin material. The first conductive member 11, which is preferable from the viewpoint of further expanding the pressing force measurement range, is made of a conductive rubber composed of a rubber material and a conductive filler dispersed in the rubber material. Since the first conductive member 11 is made of conductive rubber, the pressure sensing portion 1A can effectively detect the pressing force. Further, since the first conductive member 11 is made of conductive rubber, the pressure sensing portion 1A has a feeling of pressure when pressed. As the resin material, for example, at least one selected from the group consisting of styrene-based resin, silicone-based resin (for example, polydimethylpolysiloxane (PDMS) for short), acrylic-based resin, rotaxane-based resin, urethane-based resin, and the like. It may be one type of resin material. Examples of rubber materials include silicone rubber, isoprene rubber, butadiene rubber, styrene-butadiene rubber, chloroprene rubber, nitrile rubber, polyisobutylene, ethylene propylene rubber, chlorosulfonated polyethylene, acrylic rubber, fluororubber, epichlorohydrin rubber, and urethane rubber. at least one rubber material selected from the group consisting of Conductive fillers include Au (gold), Ag (silver), Cu (copper), C (carbon), ZnO (zinc oxide), In ₂ O ₃ (indium (III) oxide) and SnO ₂ (tin (IV) oxide). )). Also, a conductive layer may be used instead of or in addition to the conductive filler. Specifically, it is a first conductive member comprising a resin structure (especially a rubber structure) made of the above-described resin material (especially a rubber material) and a conductive layer provided on the surface thereof by applying a conductive ink or the like. good too.

The thickness of the first conductive member 11 is not particularly limited as long as the capacitance between the first conductive member 11 and the second conductive member 12 changes due to a pressing force from the outside. Hereinafter, it is preferably 500 μm or more and 1 cm or less, and for example, 1 mm is more preferable.

The first conductive member 11 typically has a sheet-like or plate-like shape, but the first conductive member 11 is located at a corresponding position of the second conductive member 12 (eg, directly above the second conductive member 12 as in FIG. 1A). As long as at least part of the member 11 is arranged, it may have any shape, for example, it may have an elongated shape (for example, linear).

The first conductive member 11 is preferably connected to the ground (ground, 0 V) of the detector from the viewpoint of noise prevention during measurement of the pressing force.

The first conductive member 11 can be obtained by the following method. For example, first, a composite material is obtained by adding a conductive filler to a solution or raw material solution of a desired resin material (rubber material). Next, the composite material is applied onto a release substrate, dried, cured (crosslinked) if desired, and then released from the release substrate to obtain the first conductive member.

The first conductive member 11 can also be obtained by the following alternative method. For example, first, a solution or raw material solution of a desired resin material (rubber material) is applied onto a release substrate, dried, and optionally cured (crosslinked). Next, an ink containing a conductive filler is applied to the surface of the obtained resin layer (rubber layer) to form a conductive layer, which is then separated from the release substrate to obtain a first conductive member.

The second conductive member 12 is arranged close to the first conductive member 11 . That is, the second conductive member 12 is arranged so as to indirectly contact the first conductive member 11 via the dielectric 13 . The second conductive member 12 may be arranged so as to indirectly contact the first conductive member 11 via the dielectric 13 and the air layer.

The second conductive member 12 has at least conductive properties and functions as a so-called electrode. The second conductive member 12 is typically flexible, but may have elastic properties. Flexibility refers to the property of returning to its original shape when the force is removed, even if it is bent and deformed as a whole by an external force. Here, the external force is a normal pressing force applied to the pressure-sensitive element, and its magnitude is, for example, approximately 0.10 N/cm ² or more and approximately 100 N/cm ² or less. When the second conductive member 12 is flexible, it has an elastic modulus of, for example, more than about 10 ⁸ Pa, particularly more than 10 ⁸ Pa and 10 ¹² Pa or less, for example, about 1.2×10 ¹¹ Pa in one example. have a rate. Regarding conductive properties, the second conductive member 12 may have a resistivity sufficiently lower than the impedance of the capacitor in the desired frequency band.

The second conductive member 12 may be made of any material as long as it has at least conductive properties. If the second conductive member 12 is flexible, it may be composed of, for example, a metal body, or a glass body and a conductive layer formed on its surface or a conductive layer dispersed therein. It may be composed of a synthetic filler. Also, the second conductive member 12 may be composed of a resin body and a conductive layer formed on the surface thereof or a conductive filler dispersed in the resin body. The metal body may be an electrode member made of metal, that is, the second conductive member 12 may be made substantially of metal. The metal body includes, for example, Au (gold), Ag (silver), Cu (copper), Ni—Cr alloy (nichrome), C (carbon), ZnO (zinc oxide), In ₂ O ₃ (indium oxide (III) ) and SnO ₂ (tin(IV) oxide). The glass body is not particularly limited as long as it has a network structure of silicon oxide. For example, at least one glass material selected from the group consisting of quartz glass, soda lime glass, borosilicate glass, lead glass, etc. may comprise The resin body contains at least one resin material selected from the group consisting of styrene-based resins, silicone-based resins (e.g., polydimethylpolysiloxane (PDMS)), acrylic-based resins, rotaxane-based resins, urethane-based resins, and the like. It may consist of The conductive layer of the glass body and the resin body may be a layer formed by vapor deposition of at least one metal selected from the same group of metals as metals that can constitute the metal body, or a layer of conductive ink. It may be a layer formed by coating or the like. The conductive filler of the glass body and the resin body may contain at least one metal selected from the same group of metals as metals that can constitute the metal body. The second conductive member 12 may be made of the same conductive rubber as the first conductive member 11 if it has elastic properties.

The second conductive member 12 is generally an elongated member having an elongated shape (for example, linear). When the second conductive member 12 is a long member and is composed of a metal body, the second conductive member 12 corresponds to a metal wire or a metal wire (eg, copper wire), and the pressing force is measured. It is preferable from the viewpoint of further expanding the range and improving the pressure sensitivity. When the second conductive member 12 is an elongated member, the elongated member should be arranged without application of tension to the elongated member from the viewpoint of improving the mountability of the pressure-sensitive element on the curved surface. is preferred. For example, the elongate members are preferably arranged in waves along a constant principal direction x, as shown in FIG. 1C.

FIG. 1C is a diagram schematically showing an example of a plan view shape (elongated shape and wave shape) of the second conductive member 12 in the pressure-sensitive element 100A of FIG. 1A. It is a sketch of the member when viewed from the side of the second conductive member. The shape in plan view means the shape when viewed from above. For example, the pressure sensing portion in FIG. Perspective shape when viewed is also included.

The second conductive member 12 may be the heater element of the pressure sensitive element. When the second conductive member 12 is a heater element, the pressure sensitive element having the second conductive member 12 also functions as a heater. Specifically, when the pressure-sensitive element is installed on the surface of a steering device (for example, a steering wheel), it is possible to keep the hand holding the steering device from getting cold. A Nichrome wire is mentioned as a heater element.

The cross-sectional shape of the second conductive member 12 is not particularly limited as long as the area of the contact area is expanded by applying a pressing force, and may be, for example, a circular shape as shown in FIG. 1A, or an elliptical shape. Alternatively, it may be triangular or the like.

The cross-sectional dimension of the second conductive member 12 is not particularly limited as long as the capacitance between the second conductive member 12 and the first conductive member 11 can be measured. From the viewpoint of further expanding the pressure measurement range and improving the pressure sensitivity, it is preferably 100 μm or more and 1 mm or less, and for example, 300 μm is more preferable. When the cross-sectional dimension of the second conductive member 12 is reduced, the change in the area of the contact area is increased, and the pressure sensitivity is improved. If the cross-sectional dimension of the elongated member is increased, the pressing force can be measured over a wider range. The cross-sectional dimension of the second conductive member 12 is the maximum dimension of the cross-sectional shape. Specifically, the cross-sectional dimension of the second conductive member 12 is the maximum dimension (e.g., diameter) in a cross section perpendicular to the longitudinal direction, assuming that the second conductive member 12 has a straight shape. .

When the second conductive member 12 is particularly an elongated member, it is usually used in plurality. At this time, patterning is possible by detecting a change in capacitance between each of the plurality of second conductive members 12 and the first conductive member 11 with a detector. Patterning is to detect the pressing position as well as the pressing force. Patterning is also possible by dividing the first conductive member 11 .

When a plurality of long members are used as the second conductive member 12, the distance (pitch) p (FIG. 1C) between the adjacent long members is usually 1 mm or more and 30 mm or less, which is preferable from the viewpoint of the steering device application. is 2 mm or more and 10 mm or less, and for example, 5 mm is more preferable. When a plurality of long members are arranged in a wave shape and used as the second conductive member 12, the wave wave wavelength λ (FIG. 1C) is usually 1 mm or more and 40 mm or less, and from the viewpoint of the steering device application, preferably 2 mm or more and 20 mm. It is less than, for example, 10 mm is more preferable if one is illustrated. Further, the wave amplitude a (FIG. 1C) is usually 1 mm or more and 20 mm or less, preferably 2 mm or more and 10 mm or less from the viewpoint of the use of the steering device, and for example, 5 mm is more preferable.

Dielectric 13 completely covers the entire surface of second conductive member 12 in FIG. It is not particularly limited as long as it at least partially covers the surface of the member 12 . That the dielectric 13 at least partially covers the surface of the first conductive member 11 or the second conductive member 12 means that the dielectric 13 is either the first conductive member 11 or the second conductive member 12 . covering at least the portion between the first conductive member 11 and the second conductive member 12 on the surface of the . In other words, dielectric 13 covers at least part of the surface of first conductive member 11 or second conductive member 12 as long as it exists between first conductive member 11 and second conductive member 12 . It is good if there is Regarding the dielectric 13 , “covering” means that the dielectric 13 is integrated with the surface of either the first conductive member 11 or the second conductive member 12 while adhering to it like a film.

From the viewpoint of further simplification of the structure of the pressure-sensitive element, the dielectric 13 preferably completely covers the entire surface of either the first conductive member 11 or the second conductive member 12 . From the viewpoint of further simplification of the pressure-sensitive element structure and easy availability of pressure-sensitive element materials, it is preferable that the dielectric 13 completely covers the entire surface of the second conductive member 12 . When the dielectric 13 completely covers the entire surface of the second conductive member 12, the dielectric 13 constitutes an insulating coating of the second conductive member 12, and the dielectric 13 and the second conductive member 12 are generally , are integrated. The integrated dielectric 13 and second conductive member 12 may correspond to an insulating coated metal wire, for example, an enameled wire, an element wire. If an insulating coated metal wire is used, the pressure-sensitive element can be configured simply by arranging this between the first conductive member 11 and the base material 14 without a photolithography process such as etching. can be sufficiently achieved, and the manufacturing cost is low.

The dielectric 13 may be made of any material as long as it has at least the properties of a "dielectric". For example, the dielectric 13 may comprise resin material, ceramic material and/or metal oxide material. By way of example only, the dielectric 13 is selected from the group consisting of polypropylene resin, polyester resin (e.g., polyethylene terephthalate resin), polyimide resin, polyphenylene sulfide resin, polyvinyl formal resin, polyurethane resin, polyamideimide resin, polyamide resin, and the like. It may consist of at least one selected resin material. Alternatively, dielectric 13 may be made of at least one metal oxide material selected from the group consisting of Al ₂ O ₃ and Ta ₂ O ₅ . Dielectric 13 is typically made of a material that has a higher resistance than the impedance of the capacitor in the desired frequency band.

Dielectric 13 typically has rigid properties. Rigidity properties refer to properties that resist deformation due to external forces. Here, the external force is a normal pressing force applied to the pressure-sensitive element, and its magnitude is, for example, approximately 0.1 N/cm ² or more and approximately 100 N/cm ² or less. Dielectric 13 is generally not deformed by normal pressing forces as described above. The dielectric 13 may have a higher elastic modulus than the first conductive member 11 so as not to deform more than the first conductive member 11 when a pressing force is applied to the pressure sensitive portion. For example, if the elastic modulus of the first conductive member 11 is about 10 ⁴ Pa or more and about 10 ⁸ Pa or less, the dielectric 13 may have a higher elastic modulus.

The thickness of the dielectric 13 is not particularly limited as long as the capacitance between the first conductive member 11 and the second conductive member 12 changes due to an external pressing force, and is usually 20 nm or more and 2 mm or less. , from the viewpoint of use in a steering system, the thickness is preferably 20 nm or more and 1 mm or less, and for example, 10 μm is more preferable.

When the dielectric 13 is made of a resin material, it can be formed by a coating method in which a resin material solution is applied and dried, an electrodeposition method in which electrodeposition is performed in a resin material solution, or the like.

When the dielectric 13 is made of a metal oxide material, it can be formed by an anodizing method or the like.

The pressure sensing portion 1A may further have a substrate 14 on the side of the second conductive member 12 opposite to the first conductive member 11 side. The base material 14 may be made of any material as long as it does not inhibit the change in capacitance between the first conductive member 11 and the second conductive member 12 . The base material 14 is preferably a stretchable member having stretchability from the viewpoint of improving the mountability of the pressure-sensitive element on the curved surface. The stretchable member may be made of, for example, the same rubber material (particularly conductive rubber) described in the description of the first conductive member 11, and one example includes silicone rubber.

The thickness of the base material 14 is not particularly limited, and may be, for example, within the same range as the thickness of the first conductive member 11 described above.

The pressure sensing portion 1A may further include a restraining member 15 (see FIG. 1C) that restricts positional displacement of the second conductive member 12 in the pressure sensing portion. The restraint member 15 does not necessarily have to fix the second conductive member 12 at a predetermined position in the pressure sensing portion, but has a restraining force to the extent that the second conductive member 12 is held at a predetermined position. It's fine if you have it. Since the pressure sensing portion has the restraining member, it is possible to prevent the positional displacement of the second conductive member 12, and as a result, it is possible to reliably detect the pressing force at the predetermined position. Also, when the pressure-sensitive element is mounted on a curved surface, it is easy to alleviate distortion and prevent damage.

Although the restraining member 15 restrains the second conductive member 12 to the base material 14 in FIG. 1C, it is sufficient that the second conductive member 12 can be restrained to at least one of the first conductive member 11 and the base material 14. . That is, the binding member 15 may bind the second conductive member 12 to either the first conductive member 11 or the substrate 14, or to both. The constraint member 15 constrains the second conductive member 12 to both of the above means that the second conductive member 12 is arranged between the first conductive member 11 and the base material 14 and the first conductive member It means that the member 11, the second conductive member 12 and the base material 14 are integrated.

Specific examples of the restraint member 15 include, for example, filamentous members, partitions, adhesives, and the like. The restraining member 15 is preferably a thread-like member. When the restraining member 15 is a thread-like member, it is possible to further simplify the structure of the pressure-sensitive element while preventing the positional displacement of the second conductive member 12, and the mounting of the pressure-sensitive element on a curved surface is facilitated. improves.

The thread-like member is not particularly limited as long as it is elongated and flexible enough to sew the second conductive member 12 to the first conductive member 11 or the base material 14 as shown in FIG. 1C. It may have either conductive or non-conductive properties. As for the thread-like member, the second conductive member 12 may be sewn to at least one of the first conductive member 11 and the base material 14 . That is, the thread-like member may sew the second conductive member 12 to either the first conductive member 11 or the substrate 14, or to both. The thread member sews the second conductive member 12 to both of the above means that the second conductive member 12 is placed between the first conductive member 11 and the base material 14 and sewn together. It means that the first conductive member 11, the second conductive member 12 and the base material 14 are integrated.

A specific example of the thread-like member may be, for example, a natural or synthetic fiber that is elongated and twisted, a fishing line, or a metal thread. The thread-like member may stitch the second conductive member 12 at regular locations, for example as shown in FIG. 1C, or stitch the second conductive member 12 at any random location. good too.

Sewing of the second conductive member 12 to the first conductive member 11 or the base material 14 by the thread-like member may be achieved by plain stitching (skewer stitching), or by machine stitching using a needle thread and a bobbin thread. may be achieved. When sewing the second conductive member 12 with a thread-like member is accomplished by machine sewing, the thread-like member is composed of a needle thread and a bobbin thread, and the needle thread and the bobbin thread are engaged. When the second conductive member 12 is sewn to one of the first conductive member 11 or the substrate 14, the engagement of the top thread and bobbin thread is positioned in the first conductive member 11 or the substrate 14. be done. When the second conductive member 12 is sewn to both the first conductive member 11 and the base material 14, the engagement portion between the needle thread and the bobbin thread is between the first conductive member 11 and the base material 14. Positioned.

The partition is a member that is erected substantially parallel to the thickness direction between the first conductive member 11 and the base material 14 to form a partition between them. The partition holds the second conductive member 12 within a predetermined compartment. The partition may be composed of, for example, a similar resin material (especially a rubber material (i.e., an elastomeric material)) as described in the description of the first conductive member 11 above, and one example includes silicone rubber. The partitions may be formed in a dot shape in plan view, or may be formed in a continuous line shape. The partitions may function as spacers as described below.

The pressure sensing portion 1A may further have a spacer between the first conductive member 11 and the base material 14 to secure a gap therebetween. Since the pressure sensing portion 1A has the spacer, the first conductive member 11 quickly returns to its original shape after the pressing force is removed, thereby improving the pressing force detection speed and response speed. The spacers may be formed in a point shape in plan view, or may be formed in a continuous line shape. The spacer may be made of, for example, the same resin material (particularly a rubber material (i.e., an elastomer material)) described in the description of the first conductive member 11, and one example includes silicone rubber.

(1b) detector 2A
The detector 2</b>A is a circuit that detects pressing force based on changes in capacitance between the first conductive member 11 and the second conductive member 12 . Detector 2A is electrically connected to wiring drawn out from first conductive member 11 and wiring drawn out from second conductive member 12 via terminals T11 and T12, respectively. Detector 2A may be a control circuit, an integrated circuit, or the like. From the viewpoint of stabilizing the pressing force detection by reducing the influence of noise, it is preferable that the first conductive member 11 is connected to the ground of the detector 2A. That is, it is preferable that the terminal T11 of the detector 2A to which the wiring drawn out from the first conductive member 11 is electrically connected is further connected to the ground.

When a plurality of the second conductive members 12 are used, the detector 2A has a plurality of terminals for electrical connection with wiring drawn from each of the plurality of second conductive members 12 .

(1c) Measurement of pressing force by the pressure-sensitive element 100A In the pressure-sensitive element 100A of this embodiment, the static electricity between the terminal T11 and the terminal T12 based on the change in the area of the contact area is measured without deforming the dielectric 13. The pressing force is measured by measuring the change in capacitance. Since the change in the area of the contact area is larger than the change in the distance between the electrodes in the conventional pressure-sensitive element, especially at a small pressing force, this embodiment can measure a wide range of pressing force with a simple structure. can be done.

(Modification)
FIG. 1D schematically shows the configuration of a pressure-sensitive element 100A according to a modification of this embodiment. The configuration of this pressure-sensitive element is such that instead of covering the second conductive member 12 with the dielectric 13 , the dielectric 13 covers a portion of the main surface of the first conductive member 11 corresponding to the second conductive member 12 . It is a configuration formed in Other parts are the same as the pressure sensitive element 100A shown in FIG. 1A.

FIG. 1E is a cross-sectional view schematically showing the configuration of the pressure-sensitive portion of the pressure-sensitive element of FIG. 1D when a pressing force is applied to the pressure-sensitive portion. In the pressure-sensitive element 100A of this modified example, as shown in FIG. 1E, when a pressing force F is applied to the pressure-sensitive portion 1A, the contact area between the dielectric 13 and the second conductive member 12 increases. As a result, the capacitance C [pF] between the first conductive member 11 and the second conductive member 12 changes. Since the capacitance C [pF] and the pressing force F [N] applied to the pressure sensing portion are expressed by the above (Equation 1) and (Equation 2) respectively, the pressing force F is detected by the detector 2A. be.

Note that the dielectric 13 needs to be kept out of contact with the second conductive member 12 when the pressure F is applied to the pressure sensitive portion 1A. Otherwise, the capacitance C between the first conductive member 11 and the second conductive member 12 cannot be measured. For this purpose, for example, in the case of the pressure-sensitive element 100D shown in FIG. At this time, it is desirable to satisfy (Equation 3).

Here, π is the circular constant.

(Second embodiment)
FIG. 2 schematically shows the structure of the pressure-sensitive element 100B of this embodiment. That is, FIG. 2 is a cross-sectional view schematically showing the configuration of a pressure-sensitive element 100B according to the second embodiment. A pressure-sensitive element 100B of this embodiment includes a pressure-sensitive portion 1B to which a pressing force is applied and a detector 2B that detects the pressing force.

(2a) pressure sensing section 1B
The pressure sensing portion 1B is an embodiment of a configuration in which first conductive members and second conductive members are alternately stacked, and except for the following matters (1B-1) and (1B-2), the first conductive member It is the same as the pressure sensing part 1A of the embodiment.

(1B-1)
The pressure sensing portion 1B has two first conductive members sandwiching the second conductive member 12 from both sides. The two first conductive members of the pressure sensing portion 1B are represented by 11a and 11b in FIG. good. The first conductive members 11a and 11b are preferably made of conductive rubber and preferably have a sheet shape. Here, the conductive rubber may be the same as the conductive rubber described as the constituent material of the first conductive member 11 in the pressure sensing portion 1A.

(1B-2)
The second conductive member 12 has a dielectric 13 covering its surface. Dielectric 13 preferably completely covers the entire surface of second conductive member 12 . A plurality of second conductive members 12 are preferably used, and each of the plurality of second conductive members 12 preferably has a dielectric 13 that completely covers the entire surface.

(2b) detector 2B
The detector 2B is the same as the detector 2A of the first embodiment except for the following item (2B-1).

(2B-1)
Detector 2B is electrically connected to wiring drawn from first conductive members 11a and 11b and wiring drawn from second conductive member 12 via terminals T11a, T11b and T12, respectively. For example, two first conductive members 11a and 11b are electrically connected to each other via detector 2B. From the viewpoint of stabilizing the pressing force detection by reducing the influence of noise, the first conductive members 11a and 11b are preferably connected to the ground of the detector 2B. That is, it is preferable that the terminals T11a and T11b of the detector 2B, to which the wires drawn out from the first conductive members 11a and 11b are electrically connected, are further connected to ground.

In FIG. 2, the detector 2B has only one terminal T12 for electrical connection with wiring drawn out from one second conductive member 12 among the plurality of second conductive members 12. As shown in FIG. However, the detector 2B usually has a plurality of terminals T12 for electrical connection with wiring drawn from each of the plurality of second conductive members 12. FIG. That is, each of all the second conductive members 12 is connected to the detector 2B via wiring and terminals.

(2c) Measurement of Pressing Force by Pressure-Sensitive Element 100B In the pressure-sensitive element 100B of this embodiment, the pressing force can be measured by measuring changes in capacitance between various combinations of terminals.

For example, the group consisting of a change in capacitance between terminals T11a and T11b, a change in capacitance between terminals T11a and T12, and a change in capacitance between terminals T12 and T11b. The pressing force can be measured by measuring one or more changes selected from.

From the viewpoint of improving the pressure-sensitive sensitivity, two or more changes selected from the above group, preferably a change in the capacitance between the terminals T11a and T12 and a change in the electrostatic capacitance between the terminals T12 and T11b. It is preferable to measure the pressing force by measuring the change in capacity.

In the pressure-sensitive element 100B of the present embodiment, the first conductive member 11a and the first conductive member 11b having different elastic moduli (Young's modulus) are used to further widen the pressing force measurement range. can do. For example, when the elastic modulus of the first conductive member 11a is relatively low and the elastic modulus of the first conductive member 11b is relatively high, the first conductive member 11a is deformed and compressed first, and then the first conductive member 11a is deformed and compressed. Since the conductive member 11b is deformed, the pressing force can be measured in a wider range.

Also in the pressure-sensitive element 100B of this embodiment, the pressing force is measured by measuring the change in the capacitance between the terminals based on the change in the area of the contact area without deforming the dielectric 13. , which has a relatively simple structure and can measure a relatively wide range of pressing forces.

Since the two first conductive members 11a and 11b are used in the pressure-sensitive element 100B of this embodiment, the influence of noise is small and the pressing force can be stably detected.

In the pressure-sensitive element 100B of this embodiment, by grounding (0 V potential) the electrode with the larger disturbance noise, the pressure-sensitive element becomes more noise resistant. The electrode with the larger disturbance noise is usually the electrode on the upstream side in the pressurizing direction. This is the electrode on the downstream side. That is, as the electrodes with larger disturbance noise, for example, the upstream electrode in the case where there is no conductor above the upstream electrode in the pressurizing direction, and the conductor above the upstream electrode in the pressurizing direction. An electrode on the downstream side in the pressurizing direction when is present.

For example, when measuring only the capacitance change between the terminals T11a and T11b, when measuring only the capacitance change between the terminals T11a and T12, and when measuring only the capacitance change between the terminals T11a and T12 When measuring the change in capacitance between terminals T12 and T11b, the first conductive member 11a is grounded (0 V potential).

Further, for example, when measuring only the change in capacitance between the terminal T12 and the terminal T11b, the first conductive member 11b is grounded (0 V potential).

This prevents noise when measuring the pressing force.

Here, the meanings of the upstream side and the downstream side in the pressurizing direction described above will be described. For example, consider the case where an electrode at a predetermined position on the surface of a pressure-sensitive element is pressed by a human hand. In this case, the pressing force is transmitted from the electrode to the inside of the pressure-sensitive element. The direction in which this pressing force is transmitted is called the pressing direction. That is, the upstream side in the pressurizing direction is the electrode side, and the downstream side in the pressurizing direction is the inner side of the pressure-sensitive element.

Also, the reason why the disturbance noise of the electrode on the downstream side in the pressure direction is greater than that on the electrode on the upstream side when there is a conductor above the electrode on the upstream side in the pressure direction will be explained.

Generally, disturbance noise increases due to the parasitic capacitance of the human hand at the electrode located upstream in the pressurizing direction. However, if there is a conductor above the electrode on the upstream side in the pressure direction, the electrode on the upstream side in the pressure direction can be set to 0 V by grounding the conductor, and the parasitic power of the human hand can be reduced. Disturbance noise due to capacitance can be canceled. Therefore, in this case, the electrode on the downstream side in the pressurizing direction has greater disturbance noise.

(Third embodiment)
FIG. 3 schematically shows the configuration of the pressure-sensitive element 100C of this embodiment. That is, FIG. 3 is a cross-sectional view schematically showing the structure of a pressure-sensitive element 100C according to the third embodiment. A pressure-sensitive element 100C of this embodiment includes a pressure-sensitive portion 1C to which a pressing force is applied and a detector 2C that detects the pressing force.

(3a) pressure sensing section 1C
The pressure sensing portion 1C is an embodiment in which the first conductive members and the second conductive members are alternately stacked. Same as 1A.

(1C-1)
The pressure sensing portion 1C has second conductive members sandwiching the first conductive member 11 from both sides. The second conductive members on both sides of the first conductive member 11 are represented by 12a and 12b in FIG. may be selected. Both second conductive member 12a and second conductive member 12b preferably have dielectrics 13a and 13b that completely cover the entire surface. Dielectrics 13a and 13b may each be independently selected within the same range as dielectric 13 of pressure sensitive portion 1A.

(3b) detector 2C
The detector 2C is the same as the detector 2A of the first embodiment except for the following item (2C-1).

(2C-1)
Detector 2C is electrically connected to wiring drawn from first conductive member 11 and wiring drawn from second conductive member 12a and second conductive member 12b via terminal T11, terminal T12a and terminal T12b, respectively. It is connected to the. From the viewpoint of stabilizing the pressing force detection by reducing the influence of noise, the second conductive member 12a is preferably connected to the ground of the detector 2C. That is, it is preferable that the terminal T12a of the detector 2C to which the wiring drawn out from the second conductive member 12a is electrically connected is further grounded.

In FIG. 3, the detector 2C has a plurality of second conductive members 12a or a plurality of second conductive members 12b on each side of the first conductive member 11, one second conductive member 12a or It is described as having only one terminal (terminal T12a or terminal T12b) for electrical connection with wiring drawn out from one second conductive member 12b. However, since the detector 2C is normally electrically connected to wiring drawn from each of the plurality of second conductive members 12a or the plurality of second conductive members 12b on each of both sides of the first conductive member 11, terminal (terminal T12a or terminal T12b). That is, all the second conductive members 12a or all the second conductive members 12b on both sides of the first conductive member 11 are connected to the detector 2C via wiring and terminals, respectively.

(3c) Measurement of Pressing Force by Pressure Sensitive Element 100C In the pressure sensing element 100C of this embodiment, the pressing force can be measured by measuring changes in capacitance between various combinations of terminals.

For example, the group consisting of a change in capacitance between terminals T12a and T12b, a change in capacitance between terminals T12a and T11, and a change in capacitance between terminals T11 and T12b. The pressing force can be measured by measuring one or more changes selected from.

From the viewpoint of improving the pressure-sensitive sensitivity, two or more changes selected from the above group, preferably a change in the capacitance between the terminals T12a and T11 and a change in the electrostatic capacitance between the terminals T11 and T12b. It is preferable to measure the pressing force by measuring the change in capacity.

In measuring the change in capacitance between various combinations of terminals, when measuring the change in capacitance using the terminal T12a and the terminal T12b, the main direction of the second conductive member 12a and the second conductive member 12a By intersecting the main direction of the member 12b, it becomes possible to detect not only the pressing force but also the pressing position. When the change in capacitance is measured using the terminals T12a and T12b, when only the change in capacitance between the terminals T12a and T12b is measured, and either the terminal T12a or the terminal T12b is included. It includes the case of measuring the change in capacitance between terminals and the change in capacitance between terminals including the other.

From the viewpoint of facilitating wiring extraction, it is preferable to measure the pressing force by measuring only the change in capacitance between the terminals T12a and T12b.

In the pressure-sensitive element 100C of this embodiment as well, the pressing force can be reduced by measuring the change in the capacitance between the terminals based on the change in the area of the contact area without deforming the dielectric 13a and the dielectric 13b. Since it is measured, it is possible to measure pressing forces in a relatively wide range with a relatively simple structure.

In the pressure-sensitive element 100C of this embodiment, similarly to the pressure-sensitive element 100B, by grounding (0 V potential) the electrode with the larger disturbance noise, the pressure-sensitive element becomes more resistant to noise.

For example, when measuring only the capacitance change between the terminal T12a and the terminal T12b, when measuring only the capacitance change between the terminal T12a and the terminal T11, and when measuring only the capacitance change between the terminal T12a and the terminal T11 When measuring the change in capacitance between terminals T11 and T12b, the second conductive member 12a is grounded (0 V potential).

Further, for example, when measuring only the change in capacitance between the terminal T11 and the terminal T12b, the first conductive member 11 is grounded (0 V potential).

This prevents noise when measuring the pressing force.

Further, by sandwiching the opposing portions of the pressure-sensitive element with 0V potential, the device is resistant to external noise. That is, the second conductive member 12a and the second conductive member 12b are set to 0V potential. This prevents noise when measuring the pressing force.

In the pressure-sensitive element 100C of this embodiment, in FIG. 3, a material similar to the base material 14 of the pressure-sensitive element 100A is provided above the second conductive member 12a and/or below the second conductive member 12b. A substrate may be disposed.

(Fourth embodiment)
FIG. 4 schematically shows the configuration of the pressure-sensitive element 100D of this embodiment. FIG. 4 is a cross-sectional view schematically showing the configuration of a pressure-sensitive element 100D according to the fourth embodiment. A pressure-sensitive element 100D of this embodiment includes a pressure-sensitive portion 1D to which a pressing force is applied and a detector 2D that detects the pressing force.

(4a) pressure sensing section 1D
The pressure sensing portion 1D is an embodiment in which the first conductive members and the second conductive members are alternately stacked. Same as 1A.

(1D-1)
The pressure sensing portion 1D is obtained by repeatedly stacking the first conductive member 11 and the second conductive member 12 in the pressure sensing portion 1A. In FIG. 4, the upper and lower first conductive members are denoted by 11a and 11b, respectively, and may be independently selected within the same range as the first conductive member 11 of the pressure sensitive portion 1A. The upper and lower second conductive members are designated 12a and 12b, respectively, and may each independently be selected within the same range as the second conductive member 12 of the pressure sensitive portion 1A. Both second conductive members 12a and 12b preferably have dielectrics 13a and 13b that completely cover the entire surface. Dielectrics 13a and 13b may each be independently selected within the same range as dielectric 13 of pressure sensitive portion 1A.

(4b) Detector 2D
The detector 2D is the same as the detector 2A of the first embodiment except for the following item (2D-1).

(2D-1)
Detector 2D connects wires drawn out from first conductive members 11a and 11b, wires drawn out from second conductive members 12a and 12b, and terminals T11a, T11b, T12a, and T12b, respectively. are electrically connected via From the viewpoint of stabilizing the pressing force detection by reducing the influence of noise, the first conductive member 11a is preferably connected to the ground of the detector 2D. That is, it is preferable that the terminal T11a of the detector 2D to which the wiring drawn out from the first conductive member 11a is electrically connected is further grounded.

In FIG. 4, the detector 2D is configured such that, of the plurality of second conductive members 12a or the plurality of second conductive members 12b on each side of the first conductive member 11b, one second conductive member 12a or It has only one terminal (terminal T12a or terminal T12b) for electrical connection with wiring drawn out from one second conductive member 12b. However, since the detector 2D is normally electrically connected to wiring drawn from each of the plurality of second conductive members 12a or the plurality of second conductive members 12b on each of both sides of the first conductive member 11b, a plurality of terminals T12a or a plurality of second conductive members T12b. That is, all the second conductive members 12a or all the second conductive members 12b on each side of the first conductive member 11b are connected to the detector 2D via wiring and terminals, respectively.

(4c) Measurement of Pressing Force by Pressure-Sensitive Element 100D In the pressure-sensitive element 100D of this embodiment, the pressing force can be measured by measuring changes in capacitance between various combinations of terminals.

For example, a change in capacitance between terminals T12a and T12b, a change in capacitance between terminals T11a and T12b, a change in capacitance between terminals T11a and T12a, and a change in capacitance between terminals T12a and T12a. The pressing force is measured by measuring one or more changes selected from the group consisting of changes in capacitance between terminals T11b and changes in capacitance between terminals T11b and T12b. be able to.

From the viewpoint of improving pressure-sensitive sensitivity, two or more changes selected from the above group, preferably a change in capacitance between terminals T11a and T12a and a change in electrostatic capacitance between terminals T11b and T12b It is preferable to measure the pressing force by measuring the change in capacity.

In the pressure-sensitive element 100D of this embodiment, the area of the contact region is further increased, so the pressure-sensitive sensitivity is further improved. Moreover, by measuring between each terminal, the difference between them can also be detected, so it is possible to measure the capacitance change in more detail.

Also in this embodiment, when measuring the change in capacitance between various combinations of terminals, when measuring the change in capacitance using the terminal T12a and the terminal T12b, the main direction of the second conductive member 12a and the main direction of the second conductive member 12b, it is possible to detect the pressing force as well as the pressing position. When the change in capacitance is measured using the terminals T12a and T12b, when only the change in capacitance between the terminals T12a and T12b is measured, and either the terminal T12a or the terminal T12b is included. It includes the case of measuring the change in capacitance between terminals and the change in capacitance between terminals including the other.

From the viewpoint of facilitating wiring extraction, it is preferable to measure the pressing force by measuring only the change in capacitance between the terminals T12a and T12b.

In the pressure-sensitive element 100D of this embodiment as well, the pressing force is measured by measuring the change in the capacitance between the terminals based on the change in the area of the contact area without deforming the dielectrics 13a and 13b. Therefore, it is possible to measure pressing forces in a relatively wide range with a relatively simple structure.

In the pressure-sensitive element 100D of this embodiment, similarly to the pressure-sensitive element 100B, by setting the electrode with the larger disturbance noise to 0 V potential, the pressure-sensitive element becomes strong in noise resistance.

For example, when measuring only the change in capacitance between the terminals T11a and T11b, when measuring only the change in capacitance between the terminals T11a and T12a, between the terminals T11a and T12a and the change in capacitance between the terminals T11b and T12b, the first conductive member 11a is grounded (0 V potential). In these cases, by grounding the second conductive member 12b (0 V potential), the pressure-sensitive element is further strengthened due to noise immunity.

Further, for example, when measuring only the change in capacitance between the terminals T12a and T12b, and when measuring only the change in capacitance between the terminals T12a and T11b, the second conductive The member 12b is brought to 0V potential. This prevents noise when measuring the pressing force.

In addition, by sandwiching the opposing portions of the pressure-sensitive element with the ground (0 V potential), it becomes resistant to external noise. That is, the first conductive member 11a and the second conductive member 12b are set to 0V potential. This makes it more resistant to noise.

In the pressure-sensitive element 100D of this embodiment, a base material similar to the base material 14 of the pressure-sensitive element 100A may be arranged below the second conductive member 12b in FIG.

(Fifth embodiment)
FIG. 5 schematically shows the structure of the pressure-sensitive element 100E of this embodiment. That is, FIG. 5 is a cross-sectional view schematically showing the configuration of a pressure-sensitive element 100E according to the fifth embodiment. The pressure-sensitive element 100E of this embodiment includes a pressure-sensitive portion 1E to which a pressing force is applied and a detector 2E that detects the pressing force.

(5a) pressure sensing section 1E
The pressure sensing portion 1E is an embodiment in which the first conductive members and the second conductive members are alternately stacked. Similar to 1D.

(1E-1)
The pressure sensing portion 1E further has a first conductive member 11c below the second conductive member 12b in FIG. The first conductive member 11c may be selected within the same range as the first conductive member 11 of the pressure sensing portion 1A.

(5b) detector 2E
The detector 2E is similar to the detector 2D of the fourth embodiment except for the following item (2E-1).

(2E-1)
The detector 2E further has a terminal T11c, and is electrically connected via the terminal T11c to a wiring drawn out from the first conductive member 11c.

(5c) Measurement of Pressing Force by Pressure-Sensitive Element 100E In the pressure-sensitive element 100E of this embodiment, the pressing force can be measured by measuring changes in capacitance between various combinations of terminals.

For example, a change in capacitance between terminals T12a and T12b, a change in capacitance between terminals T11a and T11c, a change in capacitance between terminals T11a and T12a, and a change in capacitance between terminals T12a and T12a. 1 selected from the group consisting of a change in capacitance between terminals T11b, a change in capacitance between terminals T11b and T12b, and a change in capacitance between terminals T12b and T11c By measuring one or more changes, the pressing force can be measured.

From the viewpoint of improving pressure-sensitive sensitivity, two or more changes selected from the above group, preferably a change in capacitance between terminals T11a and T12a and a change in electrostatic capacitance between terminals T11b and T12b It is preferable to measure the pressing force by measuring the change in capacity.

Also in this embodiment, it is possible to detect not only the pressing force but also the pressing position when measuring the change in capacitance between various combinations of terminals. For example, when the change in capacitance is measured using the terminals T12a and T12b, the main direction of the second conductive member 12a and the main direction of the second conductive member 12b intersect each other. It becomes possible to detect the pressing position as well as the pressure. When measuring the change in capacitance using the terminals T12a and T12b, when measuring only the change in capacitance between the terminals T12a and T12b, and when measuring only the change in capacitance between the terminals T12a and T12b The case of measuring the change in capacitance between terminals including and the change in capacitance between terminals including the other is included.

From the viewpoint of facilitating wiring extraction, it is preferable to measure the pressing force by measuring only the change in capacitance between the terminals T12a and T12b.

In the pressure-sensitive element 100E of this embodiment as well, the pressing force is measured by measuring the change in capacitance between the terminals based on the change in the area of the contact area without deforming the dielectrics 13a and 13b. Therefore, it is possible to measure pressing forces in a relatively wide range with a relatively simple structure.

In the pressure-sensitive element 100E of this embodiment, similarly to the pressure-sensitive element 100B, by grounding (0 V potential) the electrode with the larger disturbance noise, the pressure-sensitive element becomes more resistant to noise.

For example, when measuring only the change in capacitance between the terminals T11a and T11c, the first conductive member 11a is grounded (0 V potential).

Further, for example, when measuring only the change in the capacitance between the terminals T11a and T12a, and when measuring the change in the capacitance between the terminals T11a and T12a and the capacitance between the terminals T11b and T12b When measuring the change in capacitance, the first conductive member 11a is set to 0V potential. In these cases, by grounding the first conductive member 11c (0 V potential), the pressure-sensitive element is further strengthened due to noise immunity.

Also, by sandwiching the opposing portions of the pressure-sensitive element 100E with a 0V potential, it becomes resistant to external noise. That is, the first conductive members 11a and 11c are grounded (0 V potential). This prevents noise when measuring the pressing force.

(Sixth embodiment)
The structure of the pressure-sensitive element 100F of this embodiment is schematically shown in FIGS. 6A and 6B. That is, FIG. 6A is a cross-sectional view schematically showing the configuration of the pressure-sensitive element according to the sixth embodiment. FIG. 6B is a schematic diagram showing the first conductive member 11 and the second conductive member 12c having the dielectric 13c in the pressure sensitive element of FIG. 6A. The pressure-sensitive element 100F of this embodiment includes a pressure-sensitive portion 1F to which a pressing force is applied and a detector 2F that detects the pressing force.

(6a) pressure sensing section 1F
The pressure sensing portion 1F is the same as the pressure sensing portion 1A of the first embodiment except for the following items (1F-1) and (1F-2).

(1F-1)
A second conductive member 12c having a different shape is used. Specifically, the second conductive member 12c may have a net shape (mesh shape) as shown in FIG. 6B, or may have a woven shape. For example, the cross-sectional dimension of the wires forming the net shape and knitted shape may be within the same range as the cross-sectional dimension of the second conductive member 12 having an elongated shape in the pressure sensing portion 1A. The opening size of the mesh shape and knitted fabric shape is not particularly limited, and is usually 0.07 mm or more and 12 mm or less, preferably 1 mm or more and 12 mm or less from the viewpoint of steering device use, and for example, 2 mm is more preferable. . The aperture size is the maximum size of the space in plan view.

The second conductive member 12c is the same as the second conductive member 12 of the pressure sensing portion 1A except that the shape is different. It may be selected from within the same range as the constituent material of the conductive member 12 .

(1F-2)
A dielectric 13c covers the surface of the second conductive member 12c. Dielectric 13c preferably completely covers the entire surface of second conductive member 12c, as shown in FIGS. 6A and 6B. The area covered by the dielectric 13c is not particularly limited as long as the dielectric 13c at least partially covers the surface of the second conductive member 12c. That the dielectric 13c at least partially covers the surface of the second conductive member 12c means that the dielectric 13c covers at least the first conductive member 11 and the second conductive member 12c on the surface of the second conductive member 12c. It refers to the state of covering the part between

(6b) detector 2F
The detector 2F is the same as the detector 2A of the first embodiment except for the following item (2F-1).

(2F-1)
The detector 2F is electrically connected to wiring drawn from the first conductive member 11 and wiring drawn from the second conductive member 12c via terminals T11 and T12c, respectively.

(6c) Measurement of pressing force by the pressure-sensitive element 100F In the pressure-sensitive element 100F of this embodiment, the pressing force can be measured by measuring the change in capacitance between the terminal T11 and the terminal T12c. can. The pressure-sensitive element 100F of this embodiment is useful as a pressure-sensitive element having a switching function because the second conductive member 12c has a net shape or a knitted shape.

Also in the pressure-sensitive element 100F of this embodiment, the pressing force is measured by measuring the change in the capacitance between the terminals based on the change in the area of the contact area without deforming the dielectric 13c. , which has a relatively simple structure and can measure a relatively wide range of pressing forces.

In this embodiment, the second conductive member has a net shape or a fabric shape, which facilitates handling of the second conductive member, thereby improving manufacturing efficiency.

(Seventh embodiment)
FIG. 7 schematically shows the structure of the pressure-sensitive element 100G of this embodiment. That is, FIG. 7 is a cross-sectional view schematically showing the structure of the pressure-sensitive element according to the seventh embodiment. A pressure-sensitive element 100G of this embodiment includes a pressure-sensitive portion 1G to which a pressing force is applied and a detector 2G for detecting the pressing force.

(7a) Pressure sensing portion 1G
The pressure sensing portion 1G is the same as the pressure sensing portion 1A of the first embodiment except for the following items (1G-1).

(1G-1)
The second conductive member 12d is made of conductive rubber. Here, the conductive rubber may be the same as the conductive rubber described as the constituent material of the first conductive member 11 in the pressure sensing portion 1A. The second conductive member 12d has elastic properties and conductive properties, and functions as a so-called electrode. Specifically, the second conductive member 12d is elastically deformed together with the first conductive member 11 by the pressing force applied to the pressure sensing portion, and the area of the contact region between the first conductive member 11 and the dielectric 13 It is sufficient that it has elastic properties such that it expands. More specifically, the first conductive member 11 of the pressure sensing portion 1G may have an elastic modulus within the same range as the first conductive member 11 of the pressure sensing portion 1A. The second conductive member 12d may also have an elastic modulus within the same range as the first conductive member 11 in the pressure sensitive portion 1A. Regarding the conductive properties, the resistivity of the second conductive member 12d may be sufficiently smaller than the impedance of the capacitance in the desired frequency band. Such resistivity can be adjusted by changing the relative proportions of the conductive filler and rubber material described above.

(7b) detector 2G
The detector 2G is the same as the detector 2A of the first embodiment except for the following item (2G-1).

(2G-1)
The detector 2G is electrically connected to wiring drawn out from the first conductive member 11 and wiring drawn out from the second conductive member 12d via terminals T11 and T12d, respectively.

(7c) Measurement of pressing force by the pressure-sensitive element 100G In the pressure-sensitive element 100G of this embodiment, the pressing force can be measured by measuring the change in capacitance between the terminal T11 and the terminal T12d. can.

In the pressure-sensitive element 100G of this embodiment, the dielectric 13 as a whole deforms as the second conductive member 12d deforms, but the thickness of the dielectric 13 does not change. Therefore, in the pressure-sensitive element 100G of this embodiment as well, the pressing force is measured by measuring the change in the capacitance between the terminals based on the change in the area of the contact area, so the structure is relatively simple. , it is possible to measure a relatively wide range of pressing forces.

(Eighth embodiment)
FIG. 8 schematically shows the structure of the pressure-sensitive element 100H of this embodiment. That is, FIG. 8 is a cross-sectional view schematically showing the configuration of a pressure-sensitive element 100H according to the eighth embodiment. A pressure-sensitive element 100H of this embodiment includes a pressure-sensitive portion 1H to which a pressing force is applied and a detector 2H for detecting the pressing force.

(8a) pressure sensing section 1H
The pressure sensing portion 1H is the same as the pressure sensing portion 1A of the first embodiment except for the following items (1H-1) and (1H-2).

(1H-1)
The second conductive member 12e is made of conductive rubber. The second conductive member 12e is the same as the second conductive member 12d in the seventh embodiment except that it may or may not have the dielectric 13 on its surface.

(1H-2)
The first conductive member 11 has a dielectric 13d on its surface. The dielectric 13d is the same as the dielectric 13 in the pressure sensitive portion 1A, except that the dielectric 13d is formed on the surface of the first conductive member 11. As shown in FIG. For example, the constituent material of the dielectric 13d may be selected from within the same range as the constituent material of the dielectric 13 in the pressure sensitive portion 1A. Further, for example, the thickness of the dielectric 13d may be selected from within the same range as the thickness of the dielectric 13 in the pressure sensitive portion 1A.

(8b) detector 2H
The detector 2H is similar to the detector 2A of the first embodiment except for the following item (2H-1).

(2H-1)
The detector 2H is electrically connected to wiring drawn out from the first conductive member 11 and wiring drawn out from the second conductive member 12e via terminals T11 and T12e, respectively.

(8c) Measurement of pressing force by the pressure-sensitive element 100H In the pressure-sensitive element 100H of this embodiment, the pressing force can be measured by measuring the change in capacitance between the terminal T11 and the terminal T12e. can.

Also in the pressure-sensitive element 100H of this embodiment, the pressing force is measured by measuring the change in the capacitance between the terminals based on the change in the area of the contact area without deforming the dielectric 13d. , which has a relatively simple structure and can measure a relatively wide range of pressing forces.

(Ninth embodiment)
FIG. 9A schematically shows the configuration of the pressure-sensitive element 100J of this embodiment. That is, FIG. 9A is a cross-sectional view schematically showing the structure of the pressure-sensitive element according to the ninth embodiment. The pressure-sensitive element 100J of this embodiment includes a pressure-sensitive portion 1J to which a pressing force is applied and a detector 2J for detecting the pressing force.

(9a) pressure sensing section 1J
The pressure sensing portion 1J is the same as the pressure sensing portion 1A of the first embodiment except for the following items (1J-1) and (1J-2).

(1J-1)
The pressure sensing portion 1J has two or more second conductive members with different cross-sectional dimensions. FIG. 9A shows two types of second conductive member 12f and second conductive member 12g having different cross-sectional dimensions. The two or more second conductive members having different cross-sectional dimensions are the same as the second conductive member 12 in the pressure sensing portion 1A except that they have different cross-sectional dimensions. The cross-sectional dimensions of the two or more second conductive members having different cross-sectional dimensions may be selected from the same range as the cross-sectional dimensions of the second conductive member 12 in the pressure sensing portion 1A. Each of the two or more second conductive members (12f and 12g in FIG. 9A) with different cross-sectional dimensions preferably has a dielectric material (13f and 13g in FIG. 9A) that completely covers the entire surface. The dielectrics (13f and 13g in FIG. 9A) of the two or more second conductive members (12f and 12g in FIG. 9A) having different cross-sectional dimensions are within the same range as the dielectric 13 in the pressure-sensitive portion 1A. may be selected from

(1J-2)
The pressure sensing portion 1J has two first conductive members sandwiching the second conductive members 12f and 12g from both sides. The two first conductive members of pressure sensing portion 1J are represented by 11a and 11b in FIG. good. The first conductive members 11a and 11b are preferably made of conductive rubber and preferably have a sheet shape. Here, the conductive rubber may be the same as the conductive rubber described as the constituent material of the first conductive member 11 in the pressure sensing portion 1A.

(9b) detector 2J
The detector 2J is the same as the detector 2A of the first embodiment except for the following item (2J-1).

(2J-1)
The detector 2J is electrically connected to wiring drawn from the first conductive members 11a and 11b and wiring drawn from the second conductive member 12f via terminals T11a, T11b and T12, respectively. . For example, two first conductive members 11a and 11b are electrically connected to each other via detector 2J. From the viewpoint of stabilizing the pressing force detection by reducing the influence of noise, the first conductive members 11a and 11b are preferably connected to the ground of the detector 2J. That is, it is preferable that the terminals T11a and T11b of the detector 2J, to which the wires drawn out from the first conductive members 11a and 11b are electrically connected, are further grounded.

In FIG. 9A, the detector 2J is electrically connected to wiring drawn from one of two or more second conductive members (12f and 12g) having different cross-sectional dimensions. has only one terminal T12. However, the detector 2J usually has a plurality of terminals T12 for electrical connection with wiring drawn from each of the second conductive members (12f and 12g). That is, each of all the second conductive members (12f and 12g) is connected to the detector 2J via wiring and terminals.

(9c) Measurement of Pressing Force by Pressure-Sensitive Element 100J In the pressure-sensitive element 100J of this embodiment, the pressing force can be measured by measuring changes in capacitance between various combinations of terminals.

For example, the group consisting of a change in capacitance between terminals T11a and T11b, a change in capacitance between terminals T11a and T12, and a change in capacitance between terminals T12 and T11b. The pressing force can be measured by measuring one or more changes selected from.

From the viewpoint of improving the pressure-sensitive sensitivity, two or more changes selected from the above group, preferably a change in the capacitance between the terminals T11a and T12 and a change in the electrostatic capacitance between the terminals T12 and T11b. It is preferable to measure the pressing force by measuring the change in capacity.

Also in the pressure-sensitive element 100J of this embodiment, the pressing force is measured by measuring the change in the capacitance between the terminals based on the change in the area of the contact area without deforming the dielectric. With a relatively simple structure, it is possible to measure pressing forces in a relatively wide range.

FIG. 9B is a cross-sectional view schematically showing the configuration of the pressure-sensitive portion of the pressure-sensitive element of FIG. 9A when a pressing force is applied to the pressure-sensitive portion.

In the pressure-sensitive element 100J of this embodiment, two or more types of second conductive members having different cross-sectional dimensions are used, so that the pressure sensitivity can be improved and the pressing force measurement range can be further expanded. be able to. This is clear from the fact that the application of the pressing force can effectively bring about a change in the area of the contact area even after the pressure sensing portion 1J is in the state of FIG. 9B. FIG. 9B shows that the pressing force is applied from the side of the first conductive member 11a, and due to the reaction, force also acts from the side of the first conductive member 11b.

(Tenth embodiment)
FIG. 10A schematically shows the configuration of the pressure-sensitive element 100K of this embodiment. The pressure-sensitive element 100K of this embodiment includes a pressure-sensitive portion 1K to which a pressing force is applied and a detector 2K that detects the pressing force. FIG. 10A is a cross-sectional view schematically showing the configuration of a pressure-sensitive element according to the tenth embodiment.

(10a) pressure sensing portion 1K
The pressure sensing portion 1K is the same as the pressure sensing portion 1B of the second embodiment except for the following item (1K-1).

(1K-1)
The pressure sensing portion 1K has a restraining member that restricts positional displacement of the second conductive member 12 in the pressure sensing portion. The restraining member is composed of a needle thread 151 and a bobbin thread 152, and with the second conductive member 12 disposed between the first conductive member 11a and the first conductive member 11b, the first conductive member The members 11a and 11b and the second conductive member 12 are integrated. The engagement portion between the needle thread and the bobbin thread is positioned between the first conductive member 11a and the first conductive member 11b in FIG. 10A, but is positioned in the first conductive member 11a. or may be located in the first conductive member 11b.

(10b) Detector 2K
Detector 2K is similar to detector 2B of the second embodiment.

(10c) Measurement of pressing force by the pressure-sensitive element 100K Also in the pressure-sensitive element 100K of this embodiment, changes in capacitance between terminals based on changes in the area of the contact area are measured without deforming the dielectric. Therefore, the pressing force can be measured in a relatively wide range with a relatively simple structure.

FIG. 10B is a cross-sectional view schematically showing the configuration of the pressure-sensitive portion of the pressure-sensitive element of FIG. 10A when a pressing force is applied to the pressure-sensitive portion.

In the pressure-sensitive element 100K of this embodiment, as shown in FIG. 10B, even if a pressing force is applied to the pressure-sensitive portion 1K, the needle thread 151 and the bobbin thread 152 cause the second conductive member in the pressure-sensitive portion 1K. 12 is restricted, and the second conductive member 12 is held in place with an appropriate restraining force. Therefore, the pressing force can be reliably detected at a predetermined position. Also, when the pressure-sensitive element is mounted on a curved surface, it is easy to alleviate distortion and prevent damage. FIG. 10B shows that the pressing force is applied from the side of the first conductive member 11a, and the force is also applied from the side of the first conductive member 11b due to its reaction.

(First modification)
FIG. 10C schematically shows the configuration of a pressure-sensitive element 100L according to the first modified example of this embodiment. That is, FIG. 10C is a cross-sectional view schematically showing the configuration of the pressure sensitive element 100L. The pressure-sensitive element 100L of this embodiment includes a pressure-sensitive portion 1L to which a pressing force is applied and a detector 2L for detecting the pressing force.

(10d) pressure sensing section 1L
The pressure sensing portion 1L is the same as the pressure sensing portion 1K of the tenth embodiment except for the following item (1L-1).

(1L-1)
The pressure sensing portion 1L has a restraining member that restricts positional displacement of the second conductive member 12 in the pressure sensing portion. The restraining member is composed of a needle thread 151 and a bobbin thread 152, and with the second conductive member 12 disposed between the first conductive member 11a and the first conductive member 11b, the first conductive member The members 11a and 11b and the second conductive member 12 are integrated. The needle thread 151 is passed through the through hole 150 provided in the first conductive member 11a and the through hole 150 provided in the first conductive member 11b, and the bobbin thread 152 is threaded on the outer surface side of the first conductive member 11b. engaged with. With this configuration, the through hole 150 is formed in the first conductive member 11b, and when suturing using the needle thread 151 and the bobbin thread 152, it is added to the first conductive member 11a and the first conductive member 11b. The mechanical load is small, and the through hole 150 can be small. Therefore, the pressure sensing portion 1L has excellent mechanical durability against bending.

(10e) detector 2L
Detector 2L is similar to detector 2B of the second embodiment.

(10f) Measurement of pressing force by the pressure-sensitive element 100L In the pressure-sensitive element 100L of this modified example, the change in the capacitance between the terminals based on the change in the area of the contact area is measured without deforming the dielectric. Therefore, the pressing force can be measured in a relatively wide range with a relatively simple structure.

In the pressure-sensitive element 100L of this embodiment, as shown in FIG. 10C, even if a pressing force is applied to the pressure-sensitive portion 1L, the needle thread 151 and the bobbin thread 152 cause the second conductive member in the pressure-sensitive portion 1L. 12 is restricted, and the second conductive member 12 is held in place with an appropriate restraining force. Therefore, the pressing force can be reliably detected at a predetermined position. Also, when the pressure-sensitive element is mounted on a curved surface, it is easy to alleviate distortion and prevent damage.

(Second modification)
FIG. 10D schematically shows the configuration of a pressure-sensitive element 100M according to the second modification of this embodiment. That is, FIG. 10D is a cross-sectional view schematically showing the configuration of the pressure sensitive element 100M. The pressure-sensitive element 100M of this embodiment includes a pressure-sensitive portion 1M to which a pressing force is applied and a detector 2M for detecting the pressing force.

(10g) pressure sensing part 1M
The pressure sensing portion 1M is the same as the pressure sensing portion 1L of the tenth embodiment except for the following item (1M-1).

(1M-1)
The pressure sensing portion 1M has a restraining member that restricts positional displacement of the second conductive member 12 in the pressure sensing portion. The restraining member is composed of a needle thread 151 and bobbin threads 153,154. The second conductive member 12 is locked to the first conductive member 11b by a bobbin thread 153. As shown in FIG. The first conductive member 11 a and the first conductive member 11 b are stitched together with a needle thread 151 and a bobbin thread 154 . The upper thread 151 passes through the through hole 150 provided in the first conductive member 11a and the through hole 150 provided in the first conductive member 11b, and is threaded onto the outer surface side of the first conductive member 11b. engaged with. The bobbin thread 153 that locks the second conductive member 12 to the first conductive member 11 b is separate from the needle thread 151 and the bobbin thread 154 . Thereby, the second conductive member 12 can be positioned in advance with respect to the first conductive member 11b, and displacement of the second conductive member 12 is suppressed when suturing with the needle thread 151. be able to. As a result, the second conductive member 12 and the dielectric 13 can be prevented from being damaged when suturing with the needle thread 151, and the manufacturing yield and quality of the pressure sensing portion 1M are improved.

(10h) Detector 2M
Detector 2M is similar to detector 2B of the second embodiment.

(10i) Measurement of pressing force by the pressure-sensitive element 100M Also in the pressure-sensitive element 100M of this embodiment, the change in capacitance between terminals based on the change in the area of the contact area is measured without deforming the dielectric. Therefore, the pressing force can be measured in a relatively wide range with a relatively simple structure.

In the pressure-sensitive element 100M of this embodiment, as shown in FIG. 10D, even if a pressing force is applied to the pressure-sensitive portion 1M, the needle thread 151 and the bobbin thread 152 cause the second conductive member in the pressure-sensitive portion 1K. 12 is restricted, and the second conductive member 12 is held in place with an appropriate restraining force. Therefore, the pressing force can be reliably detected at a predetermined position. Also, when the pressure-sensitive element is mounted on a curved surface, it is easy to alleviate distortion and prevent damage.

(Eleventh embodiment)
In this embodiment, in the above-described first to tenth embodiments, a plurality of first conductive members (11, 11a, 11b, 11c) are provided on the side facing the second conductive members (12, 12a, 12b). It includes an aspect having a protrusion of. In this embodiment, the second conductive member typically has a dielectric 13 covering its surface. The dielectric of the second conductive member preferably completely covers the entire surface of the second conductive member.

As shown in FIGS. 11A and 11B, the first conductive member has a plurality of protrusions 20 on the side facing the second conductive member, thereby improving the pressure sensitivity. Specifically, when a pressing force is applied to the pressure-sensitive portion, the change in the area of the contact area between the first conductive member and the dielectric increases, thereby improving the pressure-sensitive sensitivity. If the pressure sensitivity is improved, for example, it becomes possible to detect even a very small pressing force that is difficult to detect in the conventional art. Accordingly, it becomes possible to accurately detect the start of application of the pressing force.

FIG. 11A is an enlarged cross-sectional view schematically showing a first conductive member and a second conductive member having a dielectric 13 on its surface in an example of the pressure-sensitive element according to the eleventh embodiment of the present disclosure. In FIG. 11A, the first conductive member has a plurality of protrusions 20 on one side. Such a first conductive member may correspond to the following first conductive member.

The first conductive member 11 in FIGS. 1A, 6A and 7. FIG.

First conductive members 11a and 11b in FIGS. 2, 9A and 10A.

A first conductive member 11a in FIG.

First conductive members 11a and 11c in FIG.

First conductive members 11a and 11b in FIGS. 9A and 10A.

FIG. 11B is an enlarged cross-sectional view schematically showing a first conductive member and a second conductive member having a dielectric 13 on its surface in another example of the pressure-sensitive element according to the eleventh embodiment of the present disclosure; be. In FIG. 11B, the first conductive member has a plurality of protrusions 20 on both sides. Such a first conductive member may correspond to the following first conductive member.

A first conductive member 11 in FIG.

The first conductive member 11b in FIGS. 4 and 5. FIG.

In this embodiment, the first conductive member 11 (11a to 11c) is the same as the first conductive member of the above-described embodiment, except that it has a protrusion 20. As shown in FIG. In this embodiment, the second conductive members 12 (12a-12g), dielectrics 13 (13a-13g) and other configurations are the same as in the previous embodiments.

The protrusion 20 is generally made of the same material as the first conductive member, preferably made of conductive rubber. Projection 20 typically has similar elastic and conductive properties as the first conductive member. As shown in FIGS. 11A and 11B, for example, the protrusion 20 has a form that protrudes from the base portion 110 of the first conductive member 11 toward the arrangement side of the second conductive member 12 and the dielectric 13. ing. In other words, the first conductive member 11 has an uneven surface on which the second conductive member 12 and the dielectric 13 are arranged. The number of protrusions 20 of the first conductive member 11 is usually at least one. Two or more protrusions 20 are provided, and therefore the first conductive member 11 may have a plurality of protrusions 20 . Due to the aspect in which the plurality of protrusions 20 are provided, the entire surface of the first conductive member 11 has an uneven shape, and the protrusions in the uneven shape correspond to the protrusions 20 . The base portion 110 of the first conductive member 11 is the portion without protrusions.

The protrusion 20 of the first conductive member 11 may have a tapered shape. Specifically, the protrusion 20 of the first conductive member 11 may have a tapered shape in which the width dimension is gradually reduced toward the tip (see FIGS. 11A and 11B). As shown in FIGS. 11A and 11B, for example, the protrusion 20 may have a frustum shape such as a truncated cone or a square pyramid as a whole.

The height dimension of the protrusion 20 may be any dimension as long as the capacitance between the first conductive member 11 and the second conductive member 12 changes due to the pressing force from the outside. Also, the plurality of protrusions 20 may be arranged regularly. The pitch dimension of the plurality of protrusions 20 is also not particularly limited as long as the capacitance between the first conductive member 11 and the second conductive member 12 changes due to the pressing force from the outside. When the first conductive member 11 has the protrusion 20 , the concept of the first conductive member 11 includes the protrusion 20 . That is, the protrusion 20 forms part of the first conductive member 11 . Therefore, the thickness of the first conductive member 11 also includes the height dimension of the protrusion 20 .

A plurality of protrusions 20 are usually formed on the surface of the sheet-shaped first conductive member 11 . The modulus of elasticity of the plurality of protrusions 20 may be locally changed according to the formation position of the sheet shape. As a result, even minute loads can be measured, and the pressure sensitivity is improved.

In one protrusion 20, the elastic modulus may be locally changed in the height direction. This makes it possible to design sensitivity linearity, and the pressure-sensitive element has higher sensitivity and linearity. Here, linearity means that there is a proportional relationship between the value of the pressing force and the measured value of the capacitance. If the pressure-sensitive element has linearity, the pressing force value can be obtained with higher accuracy.

The protrusion 20 can be formed by performing the following processes in the manufacturing method of the first conductive member 11 described in the first embodiment. That is, during drying or curing after applying a solution of a resin material (rubber material), a raw material solution, or a composite material, a mold having a desired uneven pattern is pressed. Thereby, the first conductive member 11 having the protrusion 20 is formed. Depending on the shape of the concave-convex pattern of the mold used, the plurality of pillar-shaped protrusions may have various shapes (for example, cylindrical shape, conical shape, truncated cone shape, quadrangular truncated pyramid shape, hemispherical shape, lattice shape, etc.). can have

The first conductive member 11 having the protrusions 20 can be obtained using nanoimprint technology. The nanoimprint technology is a technology in which a mold having a concave-convex pattern is pressed against a resin body of a material to be transferred, and a pattern formed on the mold in nano order is transferred to the resin body. Such a technique can form a three-dimensional object having a finer pattern and an inclination such as a cone as compared with the lithography technique. In the nanoimprint technique, a mold having a predetermined desired uneven pattern can be used to easily control the overall shape of the first conductive member 11, the height of the protrusions, and the like. Similarly, the nanoimprint technology facilitates shape control of the projections. By controlling the shape of the projection, it is possible to make the change in the contact area between the projection 20 and the dielectric 13 in the pressure-sensitive element (the change in the contact area during pressing) particularly gentle. In other words, it is possible to control the change in capacitance when pressed, and to realize a pressure-sensitive element capable of accurately detecting the pressing force.

[Uses of the pressure-sensitive element of the present disclosure]
The pressure-sensitive element of the present disclosure can be suitably used as a sensor element in various management systems and various electronic devices.

As a management system, for example, a missing item management system (cash register, logistics management, refrigerator-related items), a car management system (seats, steering gear, switches around the console (analog input possible)), a coaching management system (shoes, clothing), security management system (all contact parts), nursing care/childcare management system (functional bedding-related products), etc. The vehicle management system is a system that can casually grasp the driving state, read the driver's state (drowsiness, psychological state, etc.) and provide feedback. The coaching management system is a system that can read the center of gravity, load distribution, etc. of the human body and instantly guide the user to a comfortable state. In a security management system, for example, when a person passes by, it is possible to simultaneously read the weight, stride length, passing speed, shoe sole pattern, etc., and by comparing the data, it is possible to identify the person. be.

Examples of electronic devices include in-vehicle devices (car navigation systems, audio devices, etc.), home appliances (electric pots, IH cooking heaters, etc.), smart phones, electronic paper, electronic book readers, and the like. By applying the pressure-sensitive element of the present disclosure to various management systems and various electronic devices as described above, touch sensor elements (pressure-sensitive sheets, operation panels, and operation switches) that are more convenient for users than ever before etc.).

(12th embodiment)
For example, a case where the pressure-sensitive element of the present disclosure is applied to a steering device for a moving body will be described in detail in the twelfth embodiment. Examples of mobile objects include automobiles, ships, and airplanes. An example of the steering device is a steering wheel shown in FIG. In FIG. 12, the handle of the steering wheel is indicated at 200 . In this case, the pressure-sensitive element is preferably provided where a person's fingers are placed when the person grips the grip part 200 with his or her hand. At this time, it is preferable that the pressure-sensitive element is provided in consideration of the front and back directions of the pressure-sensitive element so that the pressing force is applied in the direction from the first conductive member to the second conductive member. The pressure-sensitive portion of the pressure-sensitive element is usually arranged such that the first conductive member 11 is oriented outward and the second conductive member 12 is oriented inward in the positional relationship between the first conductive member 11 and the second conductive member 12 . placed in

Specifically, FIGS. 13A and 13B show an embodiment in which the pressure sensitive element 100B of the second embodiment is applied to the steering wheel of an automobile as the pressure sensitive element of the present disclosure. As shown in FIGS. 13A and 13B, the pressure sensing portion 1B of the pressure sensing element 100B is attached to the outer peripheral curved surface of the grip portion 200 of the steering wheel. At this time, in the relative positional relationship between the first conductive member 11a and the second conductive member 12, the pressure-sensitive portion 1B is oriented such that the first conductive member 11a is oriented outward and the second conductive member 12 is oriented inward. are arranged as follows. More specifically, the pressure sensing portion 1B is mounted so that the outer surface of the first conductive member 11b is in contact with the outer peripheral curved surface of the grip portion 200. As shown in FIG.

The mounting method is not particularly limited as long as the pressure-sensitive portion can be fixed to the grip portion, and for example, an adhesive is useful. In FIGS. 13A and 13B, it appears that there is a gap between the outer surface of the first conductive member 11b and the outer curved surface of the grip portion 200, but the gap is usually filled with an adhesive. .

The terminal T11a to which the first conductive member 11a is electrically connected in the pressure-sensitive element detector 2B (not shown) is preferably connected to the ground of the main body of the moving body.

The pressure-sensitive element of the present disclosure can be suitably used as a sensor element in various management systems and various electronic devices described above. By applying the pressure-sensitive element of the present disclosure to various management systems and various electronic devices as described above, touch sensor elements (pressure-sensitive sheets, operation panels, and operation switches) that are more convenient for users than ever before etc.).

1A, 1B, 1C, 1D, 1E, 1F, 1G, 1H, 1J, 1K, 1L, 1M Pressure sensing part 2A, 2B, 2C, 2D, 2E, 2F, 2G, 2H, 2J, 2K, 2L, 2M Detection Container 11, 11a-11c First conductive member 12, 12a-12g Second conductive member 13, 13a-13g Dielectric 14 Base material 15 Restraining member 20 Projection 100A, 100B, 100C, 100D, 100E, 100F, 100G , 100H, 100J, 100K, 100L, 100M Pressure-sensitive element 150 Through hole 151 Upper thread 152, 153, 154 Lower thread 200 Grip portion F Pressing force R Partial region

Claims (13)

A pressure-sensitive element comprising a pressure-sensitive part to which a pressing force is applied and a detector for detecting the pressing force,
The pressure sensing part is
a first conductive member made of an elastic sheet-like conductive rubber;
a second conductive member;
a dielectric disposed between the first conductive member and the second conductive member and covering a surface of the second conductive member ;
the second conductive member is a metal wire,
the dielectric constitutes an insulating film of the second conductive member, the dielectric and the second conductive member constitute an insulating coated metal wire, the dielectric has rigidity,
In the detector, when the pressing force is applied to the pressure sensing portion, the area of the contact region between the first conductive member or the second conductive member and the dielectric is based on a change in capacitance between the first conductive member and the second conductive member due to the expansion based on the elasticity of having
A pressure-sensitive element that detects the pressing force. 2. The pressure sensing element according to claim 1, further comprising a restraining member for restricting displacement of said second conductive member in said pressure sensing portion. 3. The pressure sensitive element according to claim 2, wherein said binding member is a thread member. 4. The pressure-sensitive element according to claim 3, wherein said thread-like member is composed of a needle thread and a bobbin thread. 5. The pressure-sensitive element according to claim 1, wherein said first conductive member has a plurality of protrusions on the side facing said second conductive member. 6. The pressure-sensitive element according to claim 1, wherein said second conductive member is an elongated member. The pressure sensitive element according to any one of claims 1 to 6, wherein said second conductive member is a flexible elongated member. 8. The pressure-sensitive element according to claim 1, wherein said second conductive member comprises two or more elongated members having different cross-sectional dimensions. The pressure sensitive element according to any one of claims 1 to 8, wherein said second conductive member is a heater element of said pressure sensitive element. The pressure sensitive element according to any one of claims 1 to 9, wherein said dielectric has a thickness of 20 nm to 2 mm. The pressure sensing portion sandwiches the second conductive member from both sides by two of the first conductive members,
said second conductive member having said dielectric covering a surface;
The pressure sensitive element according to any one of claims 1 to 10, wherein said two first conductive members are electrically connected to each other. 12. The pressure-sensitive element according to claim 1, wherein said pressure-sensitive portion has a structure in which said first conductive members and said second conductive members are alternately stacked. A steering device provided on a moving body,
The steering device is
a gripping portion;
A steering device comprising: the pressure sensitive element according to any one of claims 1 to 12 provided on a surface portion of the grip portion.

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